Varied types of valving mechanisms have been used for sealing a line through which gases and liquids and air flow to prevent reverse flow of gases, air or fluids therethrough. In the past U. S. Letters have disclosed flexible disk-like valves with a series of apertures spaced inwardly of the peripheral edge of a convex shaped disk viz. U.S. Pat. No. 2,674,262 to Bradshaw and U.S. Pat. No. 4,188,978 to DeLorenzo. The valve mechanisms disclosed in the above mentioned prior art U.S. Patents operate under reverse or backflow conditions.
The object of this invention is to produce a double action check valve which controls the flow of gases or liquids in both directions and when a sudden change in volume occurs the back pressure drops thereby closing the valve.